%I #3 Mar 30 2012 18:59:14

%S 1,-2,1,0,-3,1,0,2,-4,1,0,0,5,-5,1,0,0,-2,9,-6,1,0,0,0,-7,14,-7,1,0,0,

%T 0,2,-16,20,-8,1,0,0,0,0,9,-30,27,-9,1,0,0,0,0,-2,25,-50,35,-10,1,0,0,

%U 0,0,0,-11,55,-77,44,-11,1

%N Riordan array (1-2x,x(1-x)).

%C A signed version of A113214. Inverse of A092392. Row sums are A100051(n+1) with g.f. (1-2x)/(1-x+x^2). Diagonal sums are A117363.

%F Number triangle T(n,k)=(-1)^(n-k)(C(k,n-k)+2*C(k, n-k-1))

%e Triangle begins

%e 1,

%e -2, 1,

%e 0, -3, 1,

%e 0, 2, -4, 1,

%e 0, 0, 5, -5, 1,

%e 0, 0, -2, 9, -6, 1,

%e 0, 0, 0, -7, 14, -7, 1,

%e 0, 0, 0, 2, -16, 20, -8, 1

%K easy,sign,tabl

%O 0,2

%A _Paul Barry_, Mar 10 2006